Recent market forecasts predict that mobile data traffic will increase 39 times between 2009 and 2014, while 66% of traffic will be mobile video traffic. Mobile computing devices are continually growing and increasing in processing power; however, energy efficiency and battery life remain very important limitations of smartphones and other mobile handheld computing devices (hereinafter collectively referred to as “smartphones”). Compounding this issue, wireless data transfer consumes significant energy.
A smartphone may have multiple network interfaces, i.e., both a cellular (3G/2G) and WiFi interface. WiFi networks are very efficient in data transmission due to their high bandwidth, and are also energy efficient when the phone is sending or receiving data. However, the radio interface of WiFi consumes significant energy even when the device is not sending or receiving any data.
3G or any cellular network interfaces in general, on the other hand, have very low idle-time energy consumption. However, unlike WiFi, 3G network interfaces are typically not energy-efficient during actual data communication. Their bandwidth is also 20 times lower than that of WiFi.
Dynamically distributing network traffic over multiple access networks from/to a smartphone by selecting the most suitable access network or by concurrently utilizing all access networks may be possible via one of a (i) master/slave approach, (ii) new protocols, and (iii) gateways. In a master/slave approach, an always-connected access network could be chosen as the master network, and other access networks are used as slave networks for opportunistic routing. However, such a solution would require essentially complete control over multiple access networks, which is rarely possible.
While new protocols in various layers may be advanced to support switching among access networks, an effective solution of this type has yet to be proposed. Gateways between smartphones and the Internet could perhaps also be used for distributing network traffic among multiple access networks. However, by definition, such a solution would require deploying expensive gateways, would incur additional network latency, and would require users to configure proxy settings in applications. The inventors have demonstrated the feasibility of TCP flow migration on iPhones, but without addressing or rigorously quantifying the policies and different benefits of switching interfaces. For example, please see Seamless Flow Migration on Smartphones without Network Support—Technical Report 2010-1214, Rice University, December 2010 (Ahmad Rahmati, Clayton Shepard, Angela Nicoara, Lin Zhong, Jatinder Singh) as well as U.S. Patent Application No. 61/383,847, filed on Sep. 17, 2010, Heterogeneous Network Access on Devices with One or Multiple Network Interfaces—, in the United States of America, to Angela Nicoara, Ahmad Rahmati, Clayton Shepard, Lin Zhong, Jatinder Singh
It will be appreciated that the invention as protected is defined by the attached claims, regardless of whether the invention as claimed solves one or more of the noted deficiencies. Moreover, it is expressly noted, and should be fully appreciated by the reader, that the foregoing is not intended to be a survey or description of the prior art. Rather, it is a statement of background ideas set forth by the inventors intended to help the reader understand the following detailed description. As such, this background section provides just that—background information, not prior art information.